// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_COOKIES_PARSED_COOKIE_H_
#define NET_COOKIES_PARSED_COOKIE_H_

#include <stddef.h>

#include <string>
#include <vector>

#include "base/macros.h"
#include "net/base/net_export.h"
#include "net/cookies/cookie_constants.h"

namespace net {

class NET_EXPORT ParsedCookie {
public:
    typedef std::pair<std::string, std::string> TokenValuePair;
    typedef std::vector<TokenValuePair> PairList;

    // The maximum length of a cookie string we will try to parse
    static const size_t kMaxCookieSize = 4096;
    // The maximum number of Token/Value pairs.  Shouldn't have more than 8.
    static const int kMaxPairs = 16;

    // Construct from a cookie string like "BLAH=1; path=/; domain=.google.com"
    // Format is according to RFC 6265. Cookies with both name and value empty
    // will be considered invalid.
    ParsedCookie(const std::string& cookie_line);
    ~ParsedCookie();

    // You should not call any other methods except for SetName/SetValue on the
    // class if !IsValid.
    bool IsValid() const;

    const std::string& Name() const { return pairs_[0].first; }
    const std::string& Token() const { return Name(); }
    const std::string& Value() const { return pairs_[0].second; }

    bool HasPath() const { return path_index_ != 0; }
    const std::string& Path() const { return pairs_[path_index_].second; }
    bool HasDomain() const { return domain_index_ != 0; }
    const std::string& Domain() const { return pairs_[domain_index_].second; }
    bool HasExpires() const { return expires_index_ != 0; }
    const std::string& Expires() const { return pairs_[expires_index_].second; }
    bool HasMaxAge() const { return maxage_index_ != 0; }
    const std::string& MaxAge() const { return pairs_[maxage_index_].second; }
    bool IsSecure() const { return secure_index_ != 0; }
    bool IsHttpOnly() const { return httponly_index_ != 0; }
    CookieSameSite SameSite() const;
    CookiePriority Priority() const;

    // Returns the number of attributes, for example, returning 2 for:
    //   "BLAH=hah; path=/; domain=.google.com"
    size_t NumberOfAttributes() const { return pairs_.size() - 1; }

    // These functions set the respective properties of the cookie. If the
    // parameters are empty, the respective properties are cleared.
    // The functions return false in case an error occurred.
    // The cookie needs to be assigned a name/value before setting the other
    // attributes.
    bool SetName(const std::string& name);
    bool SetValue(const std::string& value);
    bool SetPath(const std::string& path);
    bool SetDomain(const std::string& domain);
    bool SetExpires(const std::string& expires);
    bool SetMaxAge(const std::string& maxage);
    bool SetIsSecure(bool is_secure);
    bool SetIsHttpOnly(bool is_http_only);
    bool SetSameSite(const std::string& same_site);
    bool SetPriority(const std::string& priority);

    // Returns the cookie description as it appears in a HTML response header.
    std::string ToCookieLine() const;

    // Returns an iterator pointing to the first terminator character found in
    // the given string.
    static std::string::const_iterator FindFirstTerminator(const std::string& s);

    // Given iterators pointing to the beginning and end of a string segment,
    // returns as output arguments token_start and token_end to the start and end
    // positions of a cookie attribute token name parsed from the segment, and
    // updates the segment iterator to point to the next segment to be parsed.
    // If no token is found, the function returns false.
    static bool ParseToken(std::string::const_iterator* it,
        const std::string::const_iterator& end,
        std::string::const_iterator* token_start,
        std::string::const_iterator* token_end);

    // Given iterators pointing to the beginning and end of a string segment,
    // returns as output arguments value_start and value_end to the start and end
    // positions of a cookie attribute value parsed from the segment, and updates
    // the segment iterator to point to the next segment to be parsed.
    static void ParseValue(std::string::const_iterator* it,
        const std::string::const_iterator& end,
        std::string::const_iterator* value_start,
        std::string::const_iterator* value_end);

    // Same as the above functions, except the input is assumed to contain the
    // desired token/value and nothing else.
    static std::string ParseTokenString(const std::string& token);
    static std::string ParseValueString(const std::string& value);

private:
    void ParseTokenValuePairs(const std::string& cookie_line);
    void SetupAttributes();

    // Sets a key/value pair for a cookie. |index| has to point to one of the
    // |*_index_| fields in ParsedCookie and is updated to the position where
    // the key/value pair is set in |pairs_|. Accordingly, |key| has to correspond
    // to the token matching |index|. If |value| contains invalid characters, the
    // cookie parameter is not changed and the function returns false.
    // If |value| is empty/false the key/value pair is removed.
    bool SetString(size_t* index,
        const std::string& key,
        const std::string& value);
    bool SetBool(size_t* index, const std::string& key, bool value);

    // Helper function for SetString and SetBool handling the case that the
    // key/value pair shall not be removed.
    bool SetAttributePair(size_t* index,
        const std::string& key,
        const std::string& value);

    // Removes the key/value pair from a cookie that is identified by |index|.
    // |index| refers to a position in |pairs_|.
    void ClearAttributePair(size_t index);

    // Returns false if a 'SameSite' attribute is present, but has an unrecognized
    // value. In particular, this includes attributes with empty values.
    bool IsSameSiteAttributeValid() const;

    PairList pairs_;
    // These will default to 0, but that should never be valid since the
    // 0th index is the user supplied token/value, not an attribute.
    // We're really never going to have more than like 8 attributes, so we
    // could fit these into 3 bits each if we're worried about size...
    size_t path_index_;
    size_t domain_index_;
    size_t expires_index_;
    size_t maxage_index_;
    size_t secure_index_;
    size_t httponly_index_;
    size_t same_site_index_;
    size_t priority_index_;

    DISALLOW_COPY_AND_ASSIGN(ParsedCookie);
};

} // namespace net

#endif // NET_COOKIES_COOKIE_MONSTER_H_
